Assessment of Atrial Regional Wall Motion Using Strain Doppler Imaging During Biatrial Pacing in the Bradycardia-Tachycardia Syndrome

Atrial resynchronization therapy in patients with atrial fibrillation and heart failure with and without systolic left ventricular dysfunction: a pilot study

BACKGROUND

We examined the long-term (≥ 5 years) outcomes of dual-site atrial pacing (DAP) when added to background antiarrhythmic drugs (AADs) and/or ablation in patients with refractory atrial fibrillation (AF) and heart failure (HF).

METHODS

Seventy-three patients with HF (mean NYHA HF class of 2.5) and AF refractory to AADs and/or ablation were implanted with DAP systems to achieve biatrial electrical and mechanical resynchronization (ART) and rhythm control (RC).

RESULTS

Thirty-eight patients with refractory AF and HF with preserved ejection fraction (HFpEF) and 35 with reduced ejection fraction (HFrEF) were enrolled. HFpEF patients had higher left ventricular ejection fraction compared to HFrEF (53 ± 5 vs. 31 ± 10% p < 0.001). Median follow-up for survival was 9.3 years (mean 9.0 years, SE 0.63) and was similar across subgroups (p = 0.127). After DAP, 87% maintained RC with improvement in NYHA HF class (mean 1.8) at 3 years. RC was similar in HFpEF compared with HFrEF patients (89 vs. 85% respectively, p = NS) and in paroxysmal versus persistent AF (90 vs. 85% respectively, p = NS). Total survival was superior in HFpEF compared HFrEF patients (75% in HFpEF vs. 45% in HFrEF at 5 years, and 60% in HFpEF vs. 34% in HFrEF at 10 years, p = 0.036). Survival trended to be better in patients with RC than those without RC (75 vs. 54% respectively at 5 years, p = .13).

CONCLUSIONS

ART using DAP as add on therapy improved HF and established long-term RC in many patients with HFrEF and HFpEF with refractory AF. Long-term survival rates were superior in HFpEF than HFrEF.

Quantitative description of the 3D regional mechanics of the left atrium using cardiac magnetic resonance imaging

The left atrium (LA) plays an important role in the maintenance of hemodynamic and electrical stability of the heart. One of the conditions altering the atrial mechanical function is atrial fibrillation (AF), leading to an increased thromboembolic risk due to impaired mechanical function. Preserving the regions of the LA that contribute the greatest to atrial mechanical function during curative strategies for AF is important. The purpose of this study is to introduce a novel method of regional assessment of mechanical function of the LA. We used cardiac MRI to reconstruct the 3D geometry of the LA in nine control and nine patients with paroxysmal atrial fibrillation (PAF). Regional mechanical function of the LA in pre-defined segments of the atrium was calculated using regional ejection fraction and wall velocity. We found significantly greater mechanical function in anterior, septal and lateral segments as opposed to roof and posterior segments, as well as a significant decrease of mechanical function in the PAF group. We suggest that in order to minimize the impact of the AF treatment on global atrial mechanical function, damage related to therapeutic intervention, such as catheter ablation, in those areas should be minimized.

Cardiac hemodynamics and proinflammatory cytokines during biatrial and right atrial appendage pacing in patients with interatrial block

Purpose

Interatrial block (IAB) frequently coexists with sinus node disease and is considered a risk factor of left atrial dysfunction, atrial arrhythmias, and heart failure development. Conventional right atrial appendage (RAA) pacing impairs intra- and interatrial conductions and consequently prolongs P wave duration. Biatrial (BiA) pacing helps correct IAB, but its advantageous influence remains controversial. The aim of the study was to compare the effects of BiA and RAA pacing on cardiac hemodynamics and serum concentrations of inflammatory markers and neuropeptides.

Methods

Twenty-eight patients with IAB and preserved atrio-ventricular conduction treated with BiA pacing were studied. Standard invasive hemodynamic measurements were performed during BiA and RAA pacings. Furthermore, the influence of 1 week of BiA and RAA pacing on neuropeptides: atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) and markers of inflammation: high sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), and neopterin was examined.

Results

BiA pacing resulted in significant increase of cardiac output (CO) and reduction of pulmonary capillary wedge pressure. We demonstrated significantly lower concentrations of ANP, hs-CRP, IL-6, and neopterin after 1 week of BiA in comparison to RAA pacing. BNP levels remained unchanged.

Conclusions

BiA pacing in comparison to RAA pacing improves hemodynamic performance in patients with IAB and preserved atrio-ventricular conduction. BiA pacing is associated with reduction of ANP and markers of inflammation (hs-CRP, IL-6, and neopterin).

Sex steroids and bone health status in men

Male osteoporosis is a health problem which deserves more attention as nearly 30% of osteoporotic fractures happen in men aged 50 years and above. Although men do not experience an accelerated bone loss phase and testosterone deficiency is not a universal characteristic for aged men, osteoporosis due to age-related testosterone deficiency does have a negative impact on bone health status of men. Observations from epidemiological studies indicate that elderly men with higher testosterone can preserve their BMD better and thus are less prone to fracture. Observations on men with estrogen resistance or aromatase deficiency indicate that estrogen is equally important in the maintenance of bone health status. This had been validated in several epidemiological studies which found that the relationships between estrogen and bone health indices are significant and sometimes stronger than testosterone. Studies on the relationship between quantitative ultrasound and bone remodeling markers suggest that testosterone and estrogen may have differential effects on bone, but further evidence was needed. In conclusion, both testosterone and estrogen are important in the maintenance of bone health in men.

Atrial function during different multisite atrial pacing modalities in patients with bradycardia--tachycardia syndrome

BACKGROUND

Multisite atrial pacing (MAP) was introduced to improve atrial electrical synchrony and prevent recurrence of atrial fibrillation (AF).

METHODS AND RESULTS

In the present study there were 57 patients with sinus node disease, AF recurrence and prolonged P-wave on ECG with 2 MAP modalities. In all patients 1 lead was implanted in the coronary sinus (CS) ostium area. In the right atrial appendage (RAA)+CS group (28 patients) the other atrial lead was in the RAA, and in the BB+CS group (29 patients) in the Bachmann's bundle (BB) region. Tissue Doppler was used to register the electromechanical delay (EMD) in the atrial walls and estimate the atrial contraction synchrony. Cardiac output and myocardial performance index did not differ during the 2 MAP modalities. During BB+CS, in comparison with RAA+CS pacing, the peak of the mitral atrial wave occurred earlier (P<0.01), the usual right-left atrial contraction sequence was reversed more frequently (P<0.004), all atrial EMDs except for the lateral left atrium (LA) were shorter (P<0.05), and LA synchrony was greater (P<0.001).

CONCLUSIONS

In patients treated with MAP, implanting 1 of the atrial leads in the BB area instead of the RAA has no influence on global cardiac hemodynamics, but does result in earlier LA contraction, and reversal of the typical right-left atrial contraction sequence, as well as providing greater LA contraction synchrony.